Enhanced visible-light-driven photocatalytic activities for assembled hierarchical Bi₂WO₆ microspheres by fluorine substitution

The different compositions of Bi₂WO₆ by fluorine substitution have been successfully synthesized via a two-step hydrothermal process in the absence of a surfactant. The morphology of all F-doped Bi₂WO₆ samples was similar with pure Bi₂WO₆ samples. On the basis of maintaining good morphology, the introducing fluorine element only replaced the O atoms of WO₆ octahedron in Bi₂WO₆. The effects of F- substitution on the crystal structure and photocatalytic activity of Bi₂WO₆ were investigated. For the Bi₂WO₆ samples with the different Fluorine content, their band gaps have changed obviously. All F-doped Bi₂WO₆ samples exhibited good photocatalytic activity in degradation of RhB under 500W Xe lamp light irradiation. It shows that photocatalytic activities of F-doped Bi₂WO₆ samples are relevant to band gap and F content. (paper)